This application is directed to reaction products prepared from sulfurized olefins, dialkyl hydrogen phosphites and primary alkyl amines and lubricant compositions containing same.
Reaction products of sulfurized isobutylene with a dialkyl hydrogen phosphite and an alkyl primary amine offer improved antiwear protection when compared to the sulfurized olefin itself and impart improved retention of copper corrosion protection when blended into fully formulated lubricants.
Sulfurized olefins are commonly added to lubricants to improve load-carrying properties. Esters of phosphorus acids, such as dialkyl hydrogen phosphites, are also added to improve antiwear and oxidative stability. Amino or amine containing reaction products have long been added to lubricants, for example, the reaction product of trithiones with polyamines is highly useful in lubricants as detergents. However, no reference is known to applicant of the reaction product of a sulfurized olefin with a dialkyl hydrogen phosphite and an alkyl primary amine utilized as antiwear lubricant additives.